Current Measurements in Lakes Rotorua and Rotoehu 2010 and 2011

Total Page:16

File Type:pdf, Size:1020Kb

Current Measurements in Lakes Rotorua and Rotoehu 2010 and 2011 Current measurements in Lakes Rotorua and Rotoehu 2010 and 2011 NIWA Client Report: HAM2011-015 February 2011 NIWA Project: BOP11203 Current measurements in Lakes Rotorua and Rotoehu 2010 and 2011 Max Gibbs Rod Budd Cliff Hart Scott Stephens Aslan Wright-Stow Scott Edhouse NIWA contact/Corresponding author Max Gibbs Prepared for Bay of Plenty Regional Council NIWA Client Report: HAM2011-015 February 2011 NIWA Project: BOP11203 National Institute of Water & Atmospheric Research Ltd Gate 10, Silverdale Road, Hamilton P O Box 11115, Hamilton, New Zealand Phone +64-7-856 7026, Fax +64-7-856 0151 www.niwa.co.nz All rights reserved. This publication may not be reproduced or copied in any form without the permission of the client. Such permission is to be given only in accordance with the terms of the client's contract with NIWA. This copyright extends to all forms of copying and any storage of material in any kind of information retrieval system. Contents Executive Summary iv 1. Introduction 1 2. Methods 2 2.1 Current meters 2 2.2 Lake Rotorua 3 2.3 Lake Rotoehu 4 3. Results and discussion 6 3.1 Lake Rotorua July/August 2010 6 3.1.1 Current velocity 6 3.1.2 Current direction 7 3.1.3 Wind velocity and direction 7 3.1.4 Wind-water coupling 8 3.2 Lake Rotorua November/December 2010 10 3.2.1 Current velocity 12 3.2.2 Current direction 13 3.2.3 Wind velocity and direction 13 3.2.4 Wind-water coupling 15 3.2.5 Water column decoupling 16 3.3 Lake Rotoehu January/February 2011 16 3.3.1 Wind velocity and direction 17 3.3.2 Mid-lake site current velocity and direction 19 3.3.3 Southern lake site current velocity and direction 22 3.3.4 Lake Rotoehu current synthesis 25 4. Summary 27 4.1 Lake Rotorua fully mixed 27 4.2 Lake Rotorua stratified 27 4.3 Lake Rotoehu 28 4.4 Bottom line 28 5. Acknowledgement 29 Reviewed by: Approved for release by: Dr Chris Hickey Dr Ngaire Phillips Formatting checked Executive Summary The need to be able to apply sediment capping agents to defined target areas on the lake bed from the surface of the lake, necessitates determining the strength and characteristics of lake currents that will affect their settling. Bay of Plenty Regional Council asked NIWA to measure the lake currents in Lake Rotorua when it was fully mixed and when it was thermally stratified, and to measure the lake currents in Lake Rotoehu in summer when the lake was stratified. This report presents a summary of the current meter data together with the associated wind data to aid interpretation for the three deployment, Lake Rotorua mixed (July/August 2010), Lake Rotorua stratified (November/December 2010) and Lake Rotoehu stratified (January/February 2011). During fully mixed periods in winter, the whole water column of Lake Rotorua moves in the same direction at the same velocity. Mean water velocity was around 3 cm/s reaching a maximum of 20 cm/s under strong winds. The direction of flow at the current measurement sites was in the opposite direction to the wind direction measured at Rotorua Airport, implying that the water in the lake flows around Mokoia Island as a central axle in the lake. It took about 2 days to establish a current flow from a calm lake, and about 24 hours for the lake currents to reverse when the wind direction reversed. the residual lake currents dissipated after about 3 days when the wind stopped. During thermally stratified periods, the water column of Lake Rotorua became decoupled at the thermocline with water in the upper layers moving in the opposite direction to the water in the lower layers. In general, water velocities were lower than in winter with mean velocities of around 2 to 3 cm/s reaching a maximum of around 15 cm/s. At low wind velocity, water in the lake appeared to move in slowly rotating gyres. Threshold conditions required to establish the decoupled circulation pattern were a wind velocity of >5 m/s sustained for at least 24 hours. In Lake Rotoehu, the surface waters flowed with the wind. When the lake was mixed the whole water column moved in the same direction but the current velocity decreased towards the lake bed. When the lake was stratified, the water column became decoupled at the thermocline with water in the upper layers moving with the wind while water in the lower layers moved in the opposite direction. Mean water velocities were 1 to 2 cm/s reaching a maximum of around 18 cm/s during strong winds. Under low wind conditions there was a tendency for the water in the lower layers to move towards the south. Threshold conditions required to establish the decoupled circulation pattern were a wind velocity of >4 m/s sustained for at least 3 hours. Current measurements in Lakes Rotorua and Rotoehu 2010 and 2011 iv 1. Introduction To manage phosphorus releases from the sediments of Lake Rotorua and improve the water quality of the lake, one strategy is to apply an active barrier to the sediment surface i.e., a sediment cap. Typically sediment capping agents are applied at the lake surface and settle to the lake bed forming the active barrier against phosphorus release. However, preliminary data from earlier hydrology studies on Lake Rotorua indicated that the water column is not stationary and even small lake currents have the potential to move the capping material considerable distances from the point of application as it settles. To assess the magnitude of this issue, NIWA was asked by Bay of Plenty Regional Council to measure the currents in Lake Rotorua during periods when the lake was mixed and again when the lake was thermally stratified. Current measurements were also required in Lake Rotoehu to assess their likely effect on the use of aeration to manage internal P loads from sediment release. This report presents a summary of the three current measurement periods with graphical interpretation to provide visual representations of how water moves in these lakes and the role of wind forcing. Data presented in this report is available on CD- ROM with electronic files of the full data set from each period and the associated wind record from Rotorua Airport. Current measurements in Lakes Rotorua and Rotoehu 2010 and 2011 1 2. Methods 2.1 Current meters Current measurements were made using bottom mounted Acoustic Doppler Current Profilers (ADCP) which record the water velocity and direction at several depths from about 1.5 m above the sediments to about 1 m below the lake surface. The current is measured by bouncing sound off particles in the water and calculating the velocity from the Doppler shift in the return echo of each “ping”. Because the velocity of sound in water is essentially constant, the return echo can be timed to give separate data for selected distances (depths) from the instrument. However, because of the variable distances of particles from the acoustic head, the data is recorded for a depth layer or “bin” of finite thickness – usually 1 or 2 m. Also because it requires a finite time for the ping to stop ringing in the acoustic head, there is a dead zone, close to the acoustic head, in which no data is collected. The data close to the water surface may also be corrupted by wave action. The ADCP has three acoustic heads which allows the calculation of flow direction as well as velocity. The software in the instrument can be set to calculate the velocity and direction at different depths in the water column. In these deployments each current meter was set to record a burst of data (500 pings each of 0.5 second duration) and produces an average value for these data for each depth bin from the lake bed to the surface – excluding the dead zones. These measurements were repeated at 15 minute intervals for the period of each deployment. Note: By convention, water flow directions are given as “ going towards ” whereas wind flow directions a given as “ coming from ”. Current measurements in Lakes Rotorua and Rotoehu 2010 and 2011 2 2.2 Lake Rotorua Trial plot Buoy Airport ADCP positions Airport wind station Area deeper than 15 m Cores Bathymetry of Lake Rotorua (Adapted from Irwin, 1969). Figure 1: Site map of Lake Rotorua showing the locations of the ADCP current meters beside the monitoring buoy [Buoy] and the proposed sediment capping trial plot [Trial plot] relative to the meteorological station at Rotorua Airport. Currents in Lake Rotorua were measured for four weeks when the lake was fully mixed in winter [27/07/2010 to 25/08/2010] and when the lake was thermally stratified in spring [5/11/2010 to 8/12/2010]. Two study sites were used in Lake Rotorua in July/August 2010. The first was beside the remote monitoring buoy, in a depth of 21 m, and the second was at the location of a proposed sediment capping trial plot site in a depth of 18 m (Fig. 1). The ADCP site by the buoy was intended to allow direct linkage between water currents and wind forcing using the met station on the monitoring buoy. Unfortunately, the meteorological station on the buoy did not record during the August 2010 period of monitoring. Consequently, all current data Current measurements in Lakes Rotorua and Rotoehu 2010 and 2011 3 interpretation has used the wind data record from Rotorua Airport [meteorological station Agent 1770].
Recommended publications
  • The Sedimentation and Drainage History of Haroharo Caldera and the Tarawera River System, Taupo Volcanic Zone, New Zealand
    The Sedimentation and Drainage History of Haroharo Caldera and The Tarawera River System, Taupo Volcanic Zone, New Zealand Prepared by K A Hodgson and I A Nairn Environment Bay of Plenty Operations Publication 2004/03 August 2004 5 Quay Street P O Box 364 Whakatane NEW ZEALAND ISSN 1176 - 5550 Working with our communities for a better environment Environment Bay of Plenty i Acknowledgements The Department of Conservation (Rotorua Lakes Office) permitted our studies in lake and river reserves. Fletcher Challenge Forests (and its successors) provided detailed contour maps and aerial photographs. Bryan Davy and Hugh Bibby (GNS) provided a pre- publication copy of their paper on seismic imaging in Lake Tarawera. PGSF Contract IANX0201 funded this study. Sedimentation and Drainage History, Tarawera River System Operations Publication 2004/03 Environment Bay of Plenty iii Executive Summary Haroharo caldera has been formed by the coalescence of multiple collapse structures over the last 350 kyr, the latest major collapse accompanying voluminous rhyolite pyroclastic eruptions at ~50 ka. The caldera has formed a sink for precipitation on surrounding catchments, with overflow via the Tarawera River through the Whakatane graben to the sea at ~30 km to NE. Lakes have probably always occupied at least part of the caldera floor, but the early lacustrine history is largely obscured by younger eruptives. Since 26 ka, the Haroharo, Okareka, Rotoma and Tarawera volcanic complexes have grown within the caldera during eleven eruption episodes, confining ten lakes on the caldera margins. Growth of the volcanic complexes has greatly altered drainage paths and ponding areas within and marginal to the caldera, so that the present ~700 km2 caldera catchment area is about half the ~1400 km2 area that drained into the caldera between 26 ka and 9.5 ka.
    [Show full text]
  • Lake Ōkareka 21
    Contents Purpose 1 Overview 1 Lake Rotorua 2016-2017 1 Lake Rotoehu 2016-2017 3 Lake Rotoiti 2016-2017 3 Lake Ōkāreka 2016-2017 3 Key achievements 5 Rotorua Te Arawa Lakes Annual Water Quality Results 10 Lake Rotorua 13 Lake Rotoehu 17 Lake Rotoiti 19 Lake Ōkareka 21 Actions and Outcomes for Non Deed Lakes 23 Communications and stakeholder engagement update 26 Science update 27 Land Technical Advisory Group 27 Water Quality Technical Advisory Group 27 Rotorua Te Arawa Lakes Programme – DRAFT Annual Report 2016-2017 i Environmental modelling 28 Action Plans and sewage reticulation 28 Financials 29 Rotorua Te Arawa Lakes Programme – DRAFT Annual Report 2016-2017 ii Purpose The purpose of this document is to report progress against the 2016-2017 Annual Work Programme of the Rotorua Te Arawa Lakes Programme (the Programme), for the year ending 30 June 2017. This report is in accordance with Clause 5.1 and 5.2 of Deed of Funding with the Crown, for the Programme. In this report, progress made on individual interventions is reported against the Annual Work Programme commitments. The overarching goal of the Deed of Funding Agreement is to meet community aspirations for water quality in the four Deed Funded lakes: Rotoiti, Rotorua, Ōkāreka and Rotoehu. Each of these lakes has a target water quality set by the community in the Bay of Plenty Regional Water and Land Plan. This target water quality is set by Trophic Level Index (TLI) and this report provides an update on the status of water quality across the Rotorua Te Arawa Lakes, against the targets set for all lakes, Deed and non-Deed funded.
    [Show full text]
  • Lake Rotoehu Action Plan
    Lake Rotoehu Action Plan ISSN 1175 9372 (Print) ISSN 1179 9471 (Online) Environmental Publication 2007/19 November 2007 (As amended April 2011) Lake Rotoehu Action Plan Hearing Panel Decisions 7 November 2007 Environmental Publication 2007/19 Lake Rotoehu Action Plan Environment Bay of Plenty, Rotorua District Council, Te Arawa Lakes Trust i Foreword We are pleased to release the Lake Rotoehu Action Plan, which aims to significantly improve the water quality of Lake Rotoehu through lake restoration actions over the next ten years. Lake Rotoehu is a relatively quiet lake valued for trout fishing, kayaking and some waterskiing. However since 1993 it has suffered major cyanobacterial blooms, and more recently the spread of hornwort beds through much of the shallow areas. Te Arawa value the Te Arawa Lakes and the Lakes' resources as taonga and continue to maintain their spiritual, traditional, cultural and historical relationships with their ancestral lakes. The Action Plan outlines some key actions to improve lake water quality, such as: Land use and land management changes on pastoral land to meet a nutrient loss reduction target. Implementation of Environmental Programmes to protect waterways. Hornwort biomass harvesting. Wetland construction. Rotorua District Council, Environment Bay of Plenty and Te Arawa Lakes Trust look forward to working with the Lake Rotoehu community and landowners on these actions. If these actions are achieved, there is a good chance that Lake Rotoehu could be pulled back from its eutrophic state to become a mesotrophic lake again. A key indicator that this has happened will be a decline in the extent of cyanobacterial blooms that infest the lake during the summer months.
    [Show full text]
  • Annual Report
    Annual Report 2017/2018 Bay of Plenty Regional Council, Rotorua #love our lakes Lakes Council and Te Arawa Lakes Trust. rotorualakes.co.nz Working as one to protect our lakes with funding assistance from the Ministry for the Environment. Contents Purpose 1 Overview 2 Lake Rotorua 2 Lake Rotoehu 3 Lake Okareka 4 Lake Rotoiti 4 Summary of TLI results 4 Key achievements 6 Lake operations 6 Land management 9 Policy, planning, communications and information technology 11 Sewerage 13 Rotorua Te Arawa Lakes annual water quality results 14 Introduction 14 Lake Rotorua 16 Lake Rotoehu 16 Lake Rotoiti 17 Lake Ōkāreka 17 Lake Tarawera 18 Lake Okaro 19 Lake Rotomahana 19 Lake Rerewhakaaitu 20 Lake Tikitapu 21 Lake Okataina 21 Lake Rotomā 22 Lake Rotokakahi 22 ROTORUA TE ARAWA LAKES PROGRAMME i Annual Plan of Interventions – Deed Funded Lakes 24 Lake Rotorua 24 Lake Rotoehu 29 Lake Rotoiti 31 Lake Ōkāreka 33 Te Tuapapa o ngā Wai o Te Arawa/Te Arawa Cultural Values Framework 34 Annual Plan of Interventions - Non-Deed Funded 36 Lake Tarawera 36 Lake Ōkaro 37 Lake Rotomā 37 Lake Rotokakahi 37 Lake Tikitapu 38 Financials 39 ii Annual Report 2017/2018 Purpose The purpose of this document is to report against the 2017/2018 Annual Work Plan of the Rotorua Te Arawa Lakes Programme. This report is in accordance with Clause 5.1 and 5.2 of the Deed of Funding. This report provides an update on deed funded projects, including their financial status. It also provides an update on non-deed funded projects that fall under the Programme.
    [Show full text]
  • The Hamurana Stream in Lake Rotorua: Some Potential Effects of Its Diversion on the Trout Fishery and on Summer Nutrient Dynamics
    The Hamurana Stream in Lake Rotorua: some potential effects of its diversion on the trout fishery and on summer nutrient dynamics NIWA Client Report: HAM2005-025 June 2005 NIWA Project: BOP05233 The Hamurana Stream in Lake Rotorua: some potential effects of its diversion on the trout fishery and on summer nutrient dynamics Dave Rowe Max Gibbs Eddie Bowman Stan Lodge Prepared for Environment Bay of Plenty NIWA Client Report: HAM2005-025 June 2005 NIWA Project: BOP05233 National Institute of Water & Atmospheric Research Ltd Gate 10, Silverdale Road, Hamilton P O Box 11115, Hamilton, New Zealand Phone +64-7-856 7026, Fax +64-7-856 0151 www.niwa.co.nz All rights reserved. This publication may not be reproduced or copied in any form without the permission of the client. Such permission is to be given only in accordance with the terms of the client's contract with NIWA. This copyright extends to all forms of copying and any storage of material in any kind of information retrieval system. Contents Executive Summary iv 1. Background 1 2. Size and location of the cold-water plume 3 2.1 Introduction 3 2.2 Methods 5 2.3 Results 8 2.3.1 Physical measurements 8 2.3.2 Temperature measurements 10 2.3.3 Mixing proportions 15 2.3.4 Implications for nutrient inputs 18 3. Importance of the cold-water habitat for trout 20 3.1 Introduction 20 3.2 Methods 24 3.3 Results 26 3.3.1 Hot versus cold summers 26 3.3.2 Summer changes in trout condition factor for Lake Rotorua 27 3.3.3 Differences between lakes Rotorua and Rotoehu 32 3.3.4 Water temperature effects on the fisheries.
    [Show full text]
  • Part 2 Geological History.Indd
    2. Geological History Activities Curriculum Curriculum Environmental Page Activity title level link education aspect 2a Formation of the L 3–5 Science 37 Rotorua lakes 2b Silent Card Shuffl e L 3–5 Science 39 2c Mt Ngongotaha L 3–5 Science About, In 42 2d Looking at Sediment Any level Science About, In 53 2e How Wet is your Any level Science 55 Sediment? 2f What is in your L 5 Science 58 Sediment? Relevant resources: • Rotorua’s Volcanic Past – video – hire from Rotorua Public Library • Rotorua Museum Education Resources » Te Arawa – Mai Maketu ki Tongariro » Legends, Landforms and Learning » Tarawera photo kit » Tarawera Resource kit • Pollution Busters newsletter # 5 Volcanoes • Learning Media - Building Science Concepts • Book 12 – Volcanoes: Hot Rock in a Cool World Levels: 3–4 • Book 52 – The Land Changes: Keeping Earth’s Systems in Balance: Levels: 3–4 • Learning Media – Readers » The Changing Land, Jane Buxton, ISBN 0478214162, explores how the elements can affect Earth and change its shape The Rotorua Lakes Education Resource 35 Activity 2a Formation of the Rotorua Lakes Curriculum links Science Any level 2 Resources required Science • PowerPoint presentation by Will Esler, University of Waikato (on CD) • The Life and Times of Lake Rotorua and Lake Rotoiti (see background notes) • Graphic of Rotorua lake edge 9000 years ago Method 1 View the PowerPoint (ppt) before using it with the class, or set a small group this responsibility. Identify good stopping places for discussion or questions. Have some questions already identifi ed e.g. What was the signifi cant event during this time? Why was it signifi cant? Who/what was responsible for this event occurring? If a small group has previewed the ppt then they can act as a lead questioner/facilitator for one of the groups below.
    [Show full text]
  • Lake Rotoma 17/08/2012 New Zealand Topographic Map - Topomap.Co.Nz Topomap.Co.Nz Images Sourced from LINZ Topographic Maps
    Trip Card # 004 Lake Rotoma 17/08/2012 New Zealand Topographic Map - topomap.co.nz topomap.co.nz Images Sourced from LINZ Topographic Maps. Crown Copyright Reserved. Lake Rotoma Route card No. 004 Skill level: Beginner Distance: 10 - 12 Km Map no: BE38 Start/ finish point: Boat Ramp on State Highway 30 by Whangaroa Inlet Comms coverage: Communication coverage is intermitent with VHF & phone w w w .topomap.co.nz/Print?sw =16225,6314&ne=16232,6319&z=14&t=85&s=A 4&o=Portrait Introduction: If you’re wanting peace and tran- clockwise around the lake following the shoreline, quility and a chance to explore one of the smaller if you wish to shorten your trip just cut out explor- and less intimidating lakes of Rotorua then look no ing Te Rotoiti Bay and go form one peninsula to further. Lake Rotoma is quieter than many of the the other. Heading back round the lake you’ll start others and offers it’s own character. This is a sce- to see some secluded baches nestled in the bush. nic lake paddle with a few hidden surprises. On first Keep you’re eye open for the white sculpture in the appearances the lake seems just like many others water, which is best seen when lake levels are mid but depending on the lake level you will discover a to low. Heading back towards the boat ramp you few treats can explore up the Whangaroa Outlet before exit- ing the lake. Fishing on the lake is permitted and Description: Lake Rotoma, which is is the fourth there are good trout to be had but you do need to largest lake of the 11 lakes in the Rotorua Lakes get a permit from DOC.
    [Show full text]
  • Game Bird Hunting Areas Rotorua Lakes
    Game bird hunting areas Rotorua lakes Eastern Region Lake Rotoiti Lake Rotorua Open to hunting (public land) Closed to hunting Other areas of private land might be available to be hunted by gaining permission of landowner. Lake Rotorua Open to game bird hunting with some closed areas as indicated on map. These areas are Sulphur Bay, Hamurana Stream and the lake within a radius of 800 metres of the Hamurana stream mouth and Mokoia Island plus a radius of 100 metres off the Island. When hunting on Lake Rotorua be aware of built-up areas and those used by the public and your responsibility pursuant to the Arms Act 1983. (see over) Lake Rotoiti Open to game bird hunting. Shore based hunting is only permitted on the sections of Lake Rotoiti Scenic Lake Rotoehu Reserve identified on the map, and a DOC game bird hunting permit is required. Maimais are not permitted on Lake Rotoiti. Lake Rotoehu Open to game bird hunting. Shore based hunting is only permitted on the sections of Lake Rotoehu Scenic Reserve identified on the map, and a DOC game bird hunting permit is required. Temporary maimais may be constructed but no earlier than two weeks before the beginning of the game bird hunting season. All temporary structures must be removed no later than two weeks after the close of the game bird hunting season. Lake Rotoma Open to game bird hunting. Shore based hunting is only permitted on the sections of Lake Rotoma Scenic Reserve identified on the map, and a DOC game bird hunting permit is required.
    [Show full text]
  • Marae Within the Rotorua District FF 2E2‚Yri2y2‚Y„Y‚…E Xqe2we‚Ei2y2„I2
    Marae Meeting House Whare Kai Iwi Hapu Address Suburb Apumoana Apumoana 1 & 2 * Te Ao Wheoro Ngati Tumatawera Tumatawera 27 Tarawera Road Lynmore Awahou (Tarimano) Tawakeheimoa Te Aongahoro Te Arawa Rangiwewehi Hamurana Road Hamurana Hinemihi Hinemihi Hinewai Ngati Tarawhai* Hinemihi Hona Road Ngapuna Hinemoa Point (Owhata) Tutanekai Hinemoa Te Arawa Te Rorooterangi Iri-Irikapua Parad Owhata Hinetapaturangi (Waiatuhi) Kahumatamomoe Hinetapaturangi Te Arawa Pikiao 1444 Hamurana Road Hamurana Hurunga O Te Rangi Hurungaterangi Whaingarangi Te Arawa Hurungaterangi Hurunga Avenue Ngapuna Karenga Tumahaurangi Karenga Te Arawa Karenga 38 Koutu Road Koutu Kearoa Marae Kearoa Te Uira Te Arawa Tuara 25 Apirana Road Horohoro Mataarae Mataarae Ko Te Aroha Rau Te Arawa Ngati Whaoa S Hway 5 Reporoa Mataatua Marae Mataatua Hinetai Tuhoe Tuhoe/Mataatua Mataatua Street Rotorua Mataikotare (Waiohewa) Rangiteaorere Uenukurauiri Te Arawa Rangiteaorere Mataikotare Road Rotokawa Otaramarae (Pounamunui) Houmaitawhiti Hinekukuterangi Te Arawa Hinekura 97 Whangamoa Drive Okere Falls Parawai Whatumairangi Parehina Te Arawa Tura 19 Taui Street Ngongotaha Taupari (Paruaharanui) Paruaharanui Waiwaha Te Arawa Parua 1435 Hamurana Road Hamurana Pikirangi Ohomairangi Makuratawhiti Te Arawa Turipuku 932 S Hway 30 Rotokawa Punawhakareia Uenukumairarotongo Te Aokapurangi Te Arawa Pikiao 1270 S Hway 30 Rotoiti Tupuaekura Rakeiao Maruahangaroa Te Arawa Rongomai 111 Curtis Road Rotoiti Rongomaipapa Maruahangaroa Hineteata Te Arawa Kahungunu 46 Rongomaipapa Ro Horohoro Ruamata
    [Show full text]
  • Walking and Hiking in Rotorua Bay of Plenty This Publication Is Produced by Department of Conservation and Destination Rotorua
    Walking and hiking in Rotorua Bay of Plenty This publication is produced by Department of Conservation and Destination Rotorua February 2017 Editing and design: DOC Publishing Team This publication is produced using paper sourced from well-managed, renewable and legally logged forests. All photos, unless otherwise credited, are copyright DOC. Cover photo: Walkers enjoying Redwoods walk. Photo: Adrian Hodge Contents Introduction 1 Visitor information 2 Keeping you and the environment safe 2 Fire and other emergencies 2 Geothermal hazards 2 Aquatic pests 3 Information for walkers and hikers 4 Track classifications 4 Essential gear 5 Plan and prepare 5 Camping 6 Hunting 6 Fishing 6 Restrictions 7 Dog exercise areas 7 Maps 7 For the whole family ... 8 Close to the city 8 New Zealand birds a plenty 8 Magnificent water 8 Geothermal action 9 Native Ōkataina 9 Tracks and reserves 12 Lake Tikitapu Scenic Reserve 12 Lake Ōkareka 14 Mount Ngongotaha Scenic Reserve 15 Hamurana Springs Recreation Reserve 16 Okere Falls Scenic Reserve 17 Rainbow Mountain Scenic Reserve 20 Lake Rotoiti Scenic Reserve 23 Lake Rotoma Scenic Reserve 25 Lake Okataina Scenic Reserve 26 Longer walks in Lake Okataina Scenic Reserve 29 Lake Tarawera Scenic Reserve 31 Camping around Lake Tarawera 34 Walks and tracks around Tarawera 34 Lake Rotomahana Wildlife Refuge 38 Kaharoa Conservation Area 39 Mangorewa Ecological Area 40 Mokaihaha Ecological Area 43 Te Waihou 44 Nau mai, haere mai ki te rohe o Te Waiāriki Welcome to the Rotorua Lakes area. White water rafting at Okere Falls. Photo: Kaitiaki Adventures Introduction Rotorua is a paradise for walkers and hikers.
    [Show full text]
  • Evaluation of Potential Engineering Options for Reduction of Nitrogen Inputs to Lake Rotorua
    EVALUATION OF POTENTIAL ENGINEERING OPTIONS FOR REDUCTION OF NITROGEN INPUTS TO LAKE ROTORUA R4181 EVALUATION OF POTENTIAL ENGINEERING OPTIONS FOR REDUCTION OF NITROGEN INPUTS TO LAKE ROTORUA Contract Report No. 4181 August 2017 Project Team: Jo McQueen-Watton - Report author William Shaw - Report author, peer review Prepared for: Toi Moana Bay of Plenty Regional Council P.O. Box 364 Whakatāne 99 SALA STREET, WHAKAREWAREWA, 3010, P.O. BOX 7137, TE NGAE, ROTORUA 3042 Ph 07-343-9017; Fax 07-343-9018, email [email protected], www.wildlands.co.nz CONTENTS 1. INTRODUCTION 1 2. OVERVIEW OF THE LAKE CATCHMENT 1 2.1 Ecological context 1 2.2 Geology 2 2.3 Lake Rotorua 2 2.4 Sub-catchments 4 3. KEY FACTORS AFFECTING NITROGEN REMOVAL 5 4. ASSESSMENT OF POTENTIAL TECHNOLOGIES 6 5. REJECTED TECHNOLOGIES 7 5.1 Overview 7 5.2 Nanobubbles 7 5.3 Flocculent application 8 5.4 Aeration-driven destratification 11 5.5 Lake bottom oxygenation 12 5.6 Wave barriers 13 5.7 Dredging 13 5.8 Grass carp 15 5.9 Hamurana diversion wall (with and without gates) 16 5.10 Wave barrier at Waiohewa 17 5.11 Floating wetlands 17 5.12 Removal of sewage from the catchment 19 6. POTENTIALLY FEASIBLE TECHNOLOGIES 20 6.1 Overview 20 6.2 Denitrification plant (same as Tikitere) 20 6.3 Lake weed harvesting 21 6.4 Natural wetlands: protection, maintenance and enhancement 22 6.5 Constructed wetlands 24 6.6 Denitrification beds/carbon walls 26 6.7 Watercress beds 28 6.8 Seepage wetlands and grass hedges 30 6.9 Anionic PAM blocks 32 6.10 Removal of N-fixing plant species from the catchment 33 6.11 Other considerations 35 7.
    [Show full text]
  • Walking and Hiking in Rotorua Bay of Plenty Brochure
    Walking and hiking in Rotorua Bay of Plenty Contents Introduction 1 Visitor information 2 Keeping you and the environment safe 2 Fire and other emergencies 2 Geothermal hazards 2 Aquatic pests 3 Information for walkers and hikers 4 Track classifications 4 Essential gear 5 Plan and prepare 5 Camping 6 Hunting 6 Fishing 6 Restrictions 7 Dog exercise areas 7 Maps 7 For the whole family ... 8 Close to the city 8 New Zealand birds a plenty 8 Magnificent water 8 Geothermal action 9 Native Ōkataina 9 Tracks and reserves 12 Lake Tikitapu Scenic Reserve 12 Lake Ōkareka 14 Mount Ngongotaha Scenic Reserve 15 Hamurana Springs Recreation Reserve 16 Okere Falls Scenic Reserve 17 Rainbow Mountain Scenic Reserve 20 Lake Rotoiti Scenic Reserve 23 Lake Rotoma Scenic Reserve 25 This publication is produced Lake Okataina Scenic Reserve 26 by Department of Conservation Longer walks in Lake Okataina Scenic Reserve 29 and Destination Rotorua Lake Tarawera Scenic Reserve 31 February 2017 Camping around Lake Tarawera 34 Walks and tracks around Tarawera 34 Editing and design: Lake Rotomahana Wildlife Refuge 38 DOC Publishing Team Kaharoa Conservation Area 39 This publication is produced using paper sourced from well-managed, renewable and legally Mangorewa Ecological Area 40 logged forests. Mokaihaha Ecological Area 43 All photos, unless otherwise credited, are copyright DOC. Te Waihou 44 Cover photo: Walkers enjoying the Tarawera Trail Nau mai, haere mai ki te Introduction rohe o Te Waiāriki Rotorua is a paradise for walkers and hikers. With some of the world’s most spectacular scenery, you are sure to find the track, trail or walkway that’s Welcome to the Rotorua right for you.
    [Show full text]